str1 = 'hello world'
str2 = "hello world"
str3 = '''hello
         world'''
print(str1)
print(str2)
print(str3)
print('hello\'world')
print('123--{0}---{1}'.format(4, 5))

print(f'123---{str1}')
print(f'{str1} * {str2} = {str3}')

for i in range(0, 101, 2):
    print("=========开始下载=========")
    if i == 100:
        print("下载完成")
    else:
        str4 = '*' * (i // 2) + "." * ((100 - i) // 2)
        print(f'{i}%[{str4}]')

